Air traffic controller aid

ABSTRACT

A system for assisting air traffic controllers is disclosed. The system of this invention converts data obtained by sensing devices into a spoken number or statement. This conversion is accomplished automatically without the need of an individual in the conversion chain. The spoken number or statement is stored on storage device which is coupled to a transmitter so that the data can be transmitted in spoken form to pilots or other flight personnel. The system also provides means for entering verbal statements by air traffic controllers or other authorized personnel and means for these persons to override the automatic system.

United States Patent Arnold 1 Nov. 25, 1975 AIR TRAFFIC CONTROLLER AID[76] Inventor: Abraham Arnold, Silver Spring, Md

[73] Assignee: The United States of America as represented by theSecretary of the Army, Washington, D.C.

221 Filed: Aug. 15, 1974 211 Appl. No.: 497,774

Primary Examiner-Vincent P. Canney Attorney, Agent, or Firm-Edelberg.Gibson & Murray [57] ABSTRACT A system for assisting air trafficcontrollers is disclosed. The system of this invention converts dataobtained by sensing devices into a spoken number or statement. Thisconversion is accomplished automatically without the need of anindividual in the conversion chain. The spoken number or statement isstored on storage device which is coupled to a transmitter so that thedata can be transmitted in spoken form to pilots or other flightpersonnel The system also provides means for entering verbal statementsby air traffic controllers or other authorized personnel and means forthese persons to override the automatic system.

20 Claims, 3 Drawing Figures A/D TAPE 29 TEMP 'coNvERTER PLAYER 1 f 2L1r 27 5, MASTER WIND A/D TAPE T TAPE RA 1 SPEED PLAYER T -QE s i/liirEn IS RECORDER AID TAPE (VELOQTY *oorwmmnf" PLAYER US. Patent Nov. 25, 1975FIG SENSOR SENSOR CONVERTER CONVERTER"'---'" R E i om P w. MN m V 3 6 EMm P R M P E 4 R 9 s D L SW TCH 7 fi 2 I a 6 f 2 R R am mm $-21 8 AN AAAA 6 TH Tm Ta a H 5 2 f W R 2 3 a 2 m m m A AM Am F E 2 C m C 7 W P D Iw M WE m i||| S V 2 AIR TRAFFIC CONTROLLER AID The invention describedherein may be manufactured, used, and licensed by or for the Governmentfor Governmental purposes without the payment to me of any royaltiesthereon.

BACKGROUND OF THE INVENTION This invention relates to data conversionsystems, and more particularly to data conversion systems for assistingair trafiic controllers.

At the present time all or most verbal information provided flightpersonnel from an air traffic terminal is provided manually by airtraffic controllers who speak to the flight personnel by radiotransmitter. Much of the information provided by the air trafficcontroller is information originally read from instruments and compiledin a written report from which the controller reads. Thus, thecontroller merely relays information provided. Further, many of thesebits of information remain relatively constant over a substantial periodof time.

At many airports, the air traffic has become very heavy and thecontroller is kept quite busy just handling the landings and take-offs.Thus, having to provide flight personnel with temperature readings, windvelocity, weather conditions, etc. represents an extra burden on the airtraffic controllers.

This invention provides a means for automatically providing to flightpersonnel such data as wind velocity, temperature, weather conditions,visibility, etc. With this invention the air traffic controller is notburdened with this responsibility. The information is automaticallyprovided in verbal form to flight personnel. Further, the information isautomatically updated continuously so that the information provided isalways accurate information for that time.

SUMMARY OF THE INVENTION Sensors such as wind velocity sensors,temperature sensors, weather sensors, visibility sensors, etc. arecoupled to a first storage device such as a disk record or tape or othersuitable storage medium through a converter or converters. The firststorage device has verbal information stored thereon and the converteror converters provide means for selecting the proper stored informationin response to an input from the sensors. The output of the firststorage device is coupled to the record input of a second storage devicewhich is a record/playback storage device. Thus, the verbal informationselected from the first storage device is recorded on the second storagedevice.

The second storage device is preferably a tape recorder which has anendless tape, but may also be a wire recorder having an endless wireloop or and endless film-type sound recorder or any other suitablerecorder which provides both record and playback. The playback output ofthis second storage device is connected to the input of a radiotransmitter which transmits the stored information to pilots or otherinterested flight personnel. The person wishing to receive thistransmitter information merely tunes his receiver to the frequency ofthe transmitter. The transmitter may be designed to transmitcontinuously or at repeated regular intervals. The sensors arecontinuously providing output information, thereby permitting the systemto continuously provide correct data. In other words, at any given timethe information being transmitted is the correct information for thattime. Further, this continual updating of the information isaccomplished automatically.

While the data sensed by the sensors is processed and transmittedautomatically without the need of any action on the part of an airtraffic controller, under certain conditions an air traffic controllermay want to override the automatic system or may want to augment theinformation being provided by the system. With the system of thisinvention an air traffic controller can add verbal messages to theverbal messages being provided automatically, or he can override theautomatic system if the need arises. Thus, this invention provides anautomatic system which automatically provides a substantial amount ofinformation that prior to this invention had to be provided manually byair traffic controllers. This relieves the air traffic controllers fromproviding such information, thereby permitting them to concentrate onother duties such as landing and take-off intructions.

BRIEF DESCRIPTION OF THE DRAWING A complete and full understanding ofthe objects and nature of this invention will be apparent from thefollowing detailed description of the invention when read in conjunctionwith the annexed drawing in which:

FIG. I shows the sensor and first storage device section of a firstembodiment of this invention;

FIG. 2 shows the second storage device and transmitter sections utilizedwith the apparatus of FIG. I; and

FIG. 3 shows a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 and ignoringfor the present the sensor 1x, the converter 3x and the tone arm 11,this figure shows a sensor 1 which may be, for example, a temperaturesensor coupled to a converter 3. Converter 3, which is coupled to a tonearm positioner 5, converts the reading from sensor 1 to a tone armposition value to which arm positioner 5 responds. Arm positioner 5 iscoupled to a tone arm 7 which is associated with the disk record 9.Record 9 is a disk record having concentric grooves each carrying adifferent segment of verbal information.

If sensor 1 is a temperature sensor, this sensor measures the prevailingtemperature at the air terminal and transmits this reading to converter3. Converter 3 converts this reading to a tone arm position value towhich arm positioner 5 responds to place tone arm 7 in the appropriategroove of the record 9. Record 9 contains, in verbal form, a pluralityof numerical values. Thus, if the temperature measured by sensor 1 isarm positioner 5 will place tone arm 7 in the proper position to pick upthe verbal statement 80. This verbal information is transmitted by theline 13 to the write control unit 4 of FIG. 2. FIG. 2 shows arecord/playback tape unit 12 having an endless tape 2. The tape unit 12also includes a write head 6 and a read head 8. A radio transmitter 10is coupled to read head 8. Write head 6 is coupled to write control unit4.

Endless tape 2 contains present infonnation such as station or airfieldidentification codes, statements such as temperature, degrees, and otherstatements as will become apparent. It was assumed that sensor 1 of FIG.I sensed a temperature of 80 which provided on line 13 in verbal formthe numeral 80. Write control unit, in response to this information,conditions write head 6 to record the number 80 at the appropriate timeon endless tape 2 so that endless tape 2 which contains the statement"temperature" followed by the statement degrees" will have the number 80recorded between temperature and degrees. This recorded temperatureinformation is now available at read head 8 which picks up the statementtemperature 80 degrees" and voice modulates radio transmitter whichtransmits the information to anyone tuned to the frequency oftransmitter 10. Of course, along with this temperature information thestation on air terminal identifier will also be transmitted.

Referring back to FIG. 1, this figure also shows a sensor 1x coupled bya dotted line to sensor 1. This indicates that a plurality of sensors 1through 1. may be provided. Normally, a plurality of such sensors wouldbe provided so that various information normally provided by the airtraffic controllers can be provided automatically as described abovewith reference to sensor 1. These additional sensors may include, forexample, a wind velocity sensor, a humidity sensor, a ceiling sensor, avisibility sensor, etc. In other words, any information of interest thatcan be sensed or measured can be processed by this invention byproviding appropriate sensors.

FIG. 1 also shows a converter 3x connected by a dotted line to sensor 3to indicate that a plurality of converters may be provided. If aplurality of converters are provided, the number provided would be equalto the number of sensors provided. Note, however, that only oneconverter is actually needed. If only one converter is provided, theconverter would include a well known type of mechanical or electricalswitch that would sequentially couple the plurality of sensors one at atime to the converter. Since the output of the converter is an armposition value, the single converter would position the tone arm 7 inthe proper groove in record 9 to obtain the proper numerical value foreach condition sensed. Since the switch provided in such a singleconverter is a sequencing switch which periodically repeats itssequence, write control unit 4 would be synchronized in a well knownmanner to properly sense the received information from record 9 andcontrol write head 6 and endless tape 2 in order to record the information at the appropriate place on tape 2.

As was mentioned above, endless tape 2 contains preset vergal statementsin addition to the station or airport identifiers and the assumedtemperature degree statements. These additional statements correspond tothe sensors provided. For example, for a wind speed sensor, endless tape2 would have preset thereon the statement "wind speed" followed by thestatement knots". The numerical value of the wind speed obtained fromrecord 9 would be inserted between these statements by write head 6under the control of write control unit 4. Similarly, endless tape 2would have the preset statement visibility" followed by the appropriatenumber from record 9 followed by the preset statement miles. Similarpreset statements would be provided for each sensor. Write control unit4 not only controls write head 6 so that the information from record 9is recorded at the appropriate place on endless tape 2, but also maycontrol the driving of endless tape 2 so that any portions of tape 2 notcontaining any in fomtation can be driven past read head 8 at a higherspeed than the normal playback rate with the speed reduced to normalwhen a portion of tape 2 Containing information passes by the read head8. This, of course, eliminates dead transmission time from transmitter10. In addition, write control unit 4 prevents erasure of the presetinformation and provides access to tape unit 12 for override or manualinput. For example, if an air traffic controller wishes to record somespecial information on endless tape 2 that is to be transmitted bytransmitter l0 wishes to override the system. he can do so through writecontrol unit 4.

Referring back again to FIG. 1, if individual converters are providedfor each of the sensors 1 through 1x, the outputs from each convertercould be applied to arm positioner 5. In this case, arm positioner 5would include the sequencing switch.

In place of a single tone arm, a plurality of tone arms equal in numberto the number of sensors could be associated with disk record 9 as isindicated by the tone arm 11. Each tone arm would have an associated armpositioner with the output of but one converter coupled to each armpositioner. Under such conditions, write control unit 4 of FIG. 2 wouldinclude the sequential switching means to sequentially switch theplurality of tone arms. it should also be obvious that a number of tonearms less than the number of sensors but more than one tone arm could beprovided with a plurality of converters associated with each tone arm.In other words, any combination of converters and tone arms can beprovided so long as the appropriate switching mechanisms are provided.While these various combinations can be provided, the preferableembodiment of the FIG. 1 apparatus includes but a single converter whichincludes sequential switching for switching in sequence the plurality ofsensors to a single tone arm. Providing a single converter, single tonearm and tone arm positioner reduces the complexity of the apparatus andis more economical than providing a plurality of converters or aplurality of converters and tone arms.

Some of the parameters sensed by the sensors may vary more rapidly thanis desirable from an operational standpoint. If this is the case, thesensors whose output may vary too rapidly or all the sensors can beprovided with an integrator such as an RC integrator to average theinput to converter for that particular sensor or the converter couldinclude an RC integrator or integrators if a single converter is used.If a plurality of converters are provided some or all of the converterscould include an integrator if the sensors do not include integrators.

Referring again to P10. 2, as has been mentioned the informationrecorded on endless tape 2 is transmitted by transmitter 10 which iscoupled to read head 8. From the foregoing description of the system asshown in FIGS. 1 and 2, it should be obvious that the informationrecorded on endless tape 2, except for the preset information and anymanual information and any manual information, is continuously upgradedby means of the apparatus of FIG. 1. Therefore, flight personnel havingtheir receivers tuned to the frequency of transmitter 10 will alwaysreceive up-to-date information about a particular station or airfield.Transmitter 10 can be continuously transmitting or can transmitperiodically. If the transmission is periodic rather than continuous,the transmission periods should be frequent and regular. Thetransmission periods should probably not be spaced more than 5 minutesapart so that flight personnel can obtain the information without unduedelay.

FIG. 3 shows a second embodiment of the invention. In FIG. 3, threesensors, a temperature sensor 20, a wind speed sensor 21, and a velocitysensor 22 are shown. Of course, more than three sensors can be provided.The output of sensors 20, 21 and 22 are coupled to the input of theanalog to digital (A/D) converters 23, 24 and 25 respectively. Theoutput of A/D concerter 23 is applied to the input of a tape player 26,the output of A/D converter 24 is coupled to the input of a tape player27 and the output of AID converter 25 is coupled to the input of a tapeplayer 28. The output from each of the three tape players 26, 27 and 28is coupled to a separate input of a switch 29. The single output ofswitch 29 is coupled to the input of the master tape player and recorder30. Switch 29 is a sequential switch that sequentially switches theoutput of each of the tape players 26, 27 and 28 to the input of mastertape player and recorder 30. The output of master tape player andrecorder 30 is coupled to radio transmitter 31. If more than threesensors are provided, each additional sensor will, of course, have anassociated A/D converter and tape player and switch 29 will be designedto have additional inputs to accommodate these additional tape players.

The apparatus of FIG. 3 operates in a similar fashion to the apparatusof FIGS. 1 and 2. In fact, master tape player and recorder 30 can beidentical to unit 12 of FIG. 2. Tape players 26, 27 and 28 have recordedthereon numerical information in verbal form. A/D converters 23, 24, and25 in response to input from the sensors 20, 21 and 22 respectivelyselect the proper numerals on tape players 26, 27 and 28 respectively.This number in verbal form is then transmitted from each tape player viaswitch 29 to master tape player and recorder 30. Switch 29 sequentiallyinterrogates the tape players 26, 27 and 28 to provide the informationin sequential fashion to master tape player and recorder unit 30. Unit30 is, of course, synchronized with switch 29 so that the control unitsuch as unit 4 of FIG. 2 properly controls the write head and the tapeto record the information at the appropriate place on the tape for eachsensor output. The recorded information on master tape player andrecorder unit 30 is applied to transmitter 31 via a read head for'radiotransmission to interested persons. Thus, while the apparatus of FIG. 3is somewhat different than the apparatus of FIGS. 1 and 2, particularlyFIG. 1, the overall operation of the apparatus of FIG. 3 is essentiallyidentical to the operation of the apparatus of FIGS. 1 and 2.

From the foregoing description, it should be obvious that this inventionprovides a system that automatically supplies certain data to flightpersonnel that is now supplied manually by air traffic controllers. Theability to provide such data automatically permits the air trafficcontrollers to concentrate their time and efforts on their other duties.It should also be obvious from the description that the components ofthe invention represented in block diagram form in the three figures arecomponents that are available on todays market. In other words, theinvention is made up of known components and it is the manner in whichthese components are utilized together that constitutes the inventionrather than any individual component of the system. Further, as has beenmentioned, any suitable recorder, player and player/recorder can beutilized with this invention. In other words, the invention is notlimited to the disk record and tape systems specifically disclosed.

While the invention has been shown and described with reference toparticular embodiments, it will be apparent to those skilled in the artthat various changes and modifications can be made to the embodimentsshown and described without departing from the spirit and scope of theinvention as set forth in the claims.

What is claimed is:

1. Apparatus for automatically providing air traffic control assistancecomprising:

a. at least one sensor for sensing a specific parameter and providing anoutput indicative of the value of said specific parameter;

b. an information storage device having a plurality of different verbaldata stored thereon;

c. pick-up means associated with said storage device;

d. converter means coupled to the output of said at least one sensor forconverting the output of said at least one sensor to a position value ofsaid pickup means on said storage device;

e. means coupled between said converter means and said pick-up means forpositioning said pick-up means to a specific location on saidinformation storage device in response to said position value from saidconverter means, thereby selecting a specific data bit from saidplurality of data stored on said information storage device, saidspecific data bit being a verbal statement of the value of saidparameter as measured by said at least one sensor at that time, adifferent data bit being selected each time the output of said at leastone sensor indicates that the value of said paramter has changed;

f. a record/playback storage device having a record input and a playbackoutput;

g. means to couple said pick-up means to said record input of saidrecord/playback storage device to thereby record at a specific locationon said record/playback storage device in verbal form said selected databit; and

h. a radio transmitter coupled to said playback output of saidrecord/playback storage device for transmitting said selected data bit,whereby said radio transmitter transmits said value of said parameterwith said value being constantly updated so that said value transmittedis the correct value of said parameter at the time of transmission.

2. The apparatus as defined in claim 1 wherein said record/playbackstorage device is a magnetic tape unit having an endless magnetic tape.

3. The apparatus as defined in claim 2 wherein said record input of saidrecord/playback storage device includes a conventional magnetic tapewrite head.

4. The apparatus as defined in claim 3 wherein said playback output ofsaid record/playback storage device includes a conventional magneticread head.

5. The apparatus as defined in claim 4 wherein said means to couple saidpick-up means to said record input of said record/playback storagedevice is a control unit.

6. The apparatus as defined in claim 5 wherein said endless tape haspreset verbal data stored thereon, said preset verbal data includingidentifier codes, a statement identifying said parameter and a statementof the unit by which said parameter is measured, said control unitcontrolling said endless tape and said write head in such a manner as toinsert between said statement identifying said parameter and saidstatement of said units, the value of said parameter as provided by saidpick-up means.

7. The apparatus as defined in claim 6 wherein said information storagedevice is a record disk with said plurality of different data beingcarried in concentric grooves on said record disk.

8. The apparatus as defined in claim 2 wherein said pick-up means is atone arm.

9. The appartus as defined in claim 8 wherein said means to positionsaid pick-up means is a mechanical positioner coupled to said tone armto mechanically position said tone arm to a specific location on saidrecord disk in response to the output from said converter means.

10. The apparatus as defined in claim 9 wherein a plurality of sensorsare provided, each sensor measuring a different parameter and providingan output indicative of the value of the parameter measured by thatsensor, said plurality of sensors continuously providing updated valuesof each parameter being measured.

11. The apparatus as defined in claim 10 wherein the value indicated bythe output of each of said plurality of said sensors is selected fromsaid record disk and recorded on said endless tape at a given positionon said endless tape.

12. The apparatus as defined in claim 6 wherein said information storagedevice is a tape player.

13. The apparatus as defined in claim 12 wherein said endless tape haspreset thereon in addition to said identifier code, statementsidentifying all the parameters sensed by said plurality of sensors withsaid parameter identifying statement being followed by a statement ofthe units by which each parameter is measured, the value of eachparameter as measured by each of said plurality of sensors beinginserted on said endless tape between the appropriate said parameteridentifier statement and said associated units statement.

14. The apparatus as defined in claim 13 wherein said converter means isan analog to digital converter.

15. The apparatus as defined in claim 14 wherein said pick-up means is aplayback head associated with said tape player, said playback head beingcontrolled by said analog to digital converter to pick up a specificdata bit of said plurality of data, said specific data bit being averbal statement of said parameter as measured by said at least onesensor.

16. The apparatus as defined in claim 15 wherein a plurality of sensorsare provided, a plurality of analog to digital converters equal innumber to said plurality of sensors are provided, and wherein aplurality of tape players equal in number to said plurality of analog todigital converters are provided, each one of said plurality of sensorsbeing coupled to a different one of said plurality of tape playersthrough a different one of said plurality of analog to digitalconverters.

17. The apparatus as defined in claim 16 wherein each of said pluralityof tape players has a playback head controlled by the one analog todigital converter of said plurality of analog to digital convertersassociated with that tape player.

18. The apparatus as defined in claim 17 wherein a switching meanshaving a plurality of inputs equal in number to said plurality of tapeplayers and a single output is provided, and wherein means are providedto couple each one of said plurality of said switch inputs to the outputof a different one of said tape players and means is provided to couplesaid single output to said control unit.

19. The apparatus as defined in claim 17 wherein each tape player hasrecorded thereon a plurality of different verbal data corresponding todifferent values of the parameter measured by the sensor coupled to thattape player.

20. The apparatus as defined in claim 19 wherein the value indicated bythe output of each of said plurality of said sensors is selected fromsaid associated tape player of said plurality of tape players andrecorded on said endless tape at a given position on said endless tape.

1. Apparatus for automatically providing air traffic control assistancecomprising: a. at least one sensor for sensing a specific parameter andproviding an output indicative of the value of said specific parameter;b. an information storage device having a plurality of different verbaldata stored thereon; c. pick-up means associated with said storagedevice; d. converter means coupled to the output of said at least onesensor for converting the output of said at least one sensor to aposition value of said pick-up means on said storage device; e. meanscoupled between said converter means and said pick-up means forpositioning said pick-up means to a specific location on saidinformation storage device in response to said position value from saidconverter means, thereby selecting a specific data bit from saidplurality of data stored on said information storage device, saidspecific data bit being a verbal statement of the value of saidparameter as measured by said at least one sensor at that time, adifferent data bit being selected each time the output of said at leastone sensor indicates that the value of said paramter has changed; f. arecord/playback Storage device having a record input and a playbackoutput; g. means to couple said pick-up means to said record input ofsaid record/playback storage device to thereby record at a specificlocation on said record/playback storage device in verbal form saidselected data bit; and h. a radio transmitter coupled to said playbackoutput of said record/playback storage device for transmitting saidselected data bit, whereby said radio transmitter transmits said valueof said parameter with said value being constantly updated so that saidvalue transmitted is the correct value of said parameter at the time oftransmission.
 2. The apparatus as defined in claim 1 wherein saidrecord/playback storage device is a magnetic tape unit having an endlessmagnetic tape.
 3. The apparatus as defined in claim 2 wherein saidrecord input of said record/playback storage device includes aconventional magnetic tape write head.
 4. The apparatus as defined inclaim 3 wherein said playback output of said record/playback storagedevice includes a conventional magnetic read head.
 5. The apparatus asdefined in claim 4 wherein said means to couple said pick-up means tosaid record input of said record/playback storage device is a controlunit.
 6. The apparatus as defined in claim 5 wherein said endless tapehas preset verbal data stored thereon, said preset verbal data includingidentifier codes, a statement identifying said parameter and a statementof the unit by which said parameter is measured, said control unitcontrolling said endless tape and said write head in such a manner as toinsert between said statement identifying said parameter and saidstatement of said units, the value of said parameter as provided by saidpick-up means.
 7. The apparatus as defined in claim 6 wherein saidinformation storage device is a record disk with said plurality ofdifferent data being carried in concentric grooves on said record disk.8. The apparatus as defined in claim 2 wherein said pick-up means is atone arm.
 9. The appartus as defined in claim 8 wherein said means toposition said pick-up means is a mechanical positioner coupled to saidtone arm to mechanically position said tone arm to a specific locationon said record disk in response to the output from said converter means.10. The apparatus as defined in claim 9 wherein a plurality of sensorsare provided, each sensor measuring a different parameter and providingan output indicative of the value of the parameter measured by thatsensor, said plurality of sensors continuously providing updated valuesof each parameter being measured.
 11. The apparatus as defined in claim10 wherein the value indicated by the output of each of said pluralityof said sensors is selected from said record disk and recorded on saidendless tape at a given position on said endless tape.
 12. The apparatusas defined in claim 6 wherein said information storage device is a tapeplayer.
 13. The apparatus as defined in claim 12 wherein said endlesstape has preset thereon in addition to said identifier code, statementsidentifying all the parameters sensed by said plurality of sensors withsaid parameter identifying statement being followed by a statement ofthe units by which each parameter is measured, the value of eachparameter as measured by each of said plurality of sensors beinginserted on said endless tape between the appropriate said parameteridentifier statement and said associated units statement.
 14. Theapparatus as defined in claim 13 wherein said converter means is ananalog to digital converter.
 15. The apparatus as defined in claim 14wherein said pick-up means is a playback head associated with said tapeplayer, said playback head being controlled by said analog to digitalconverter to pick up a specific data bit of said plurality of data, saidspecific data bit being a verbal statement of said parameter as measuredby said at least one sensor.
 16. The apparatus as defined in claim 15wherein a pluralitY of sensors are provided, a plurality of analog todigital converters equal in number to said plurality of sensors areprovided, and wherein a plurality of tape players equal in number tosaid plurality of analog to digital converters are provided, each one ofsaid plurality of sensors being coupled to a different one of saidplurality of tape players through a different one of said plurality ofanalog to digital converters.
 17. The apparatus as defined in claim 16wherein each of said plurality of tape players has a playback headcontrolled by the one analog to digital converter of said plurality ofanalog to digital converters associated with that tape player.
 18. Theapparatus as defined in claim 17 wherein a switching means having aplurality of inputs equal in number to said plurality of tape playersand a single output is provided, and wherein means are provided tocouple each one of said plurality of said switch inputs to the output ofa different one of said tape players and means is provided to couplesaid single output to said control unit.
 19. The apparatus as defined inclaim 17 wherein each tape player has recorded thereon a plurality ofdifferent verbal data corresponding to different values of the parametermeasured by the sensor coupled to that tape player.
 20. The apparatus asdefined in claim 19 wherein the value indicated by the output of each ofsaid plurality of said sensors is selected from said associated tapeplayer of said plurality of tape players and recorded on said endlesstape at a given position on said endless tape.